<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
		<style>
			* {
				margin: 0;
				padding: 0;
				list-style: none;
			}
			
			div {
				position: relative;
				width: 800px;
				height: 200px;
				border: 5px solid lightgreen;
				margin: 10px auto;
				overflow: hidden;
			}
			
			div ul {
				position: absolute;
				left: 0;
				top: 0;
			}
			
			div ul li {
				width: 200px;
				height: 200px;
				float: left;
			}
			
			div ul li img {
				width: 100%;
				height: 100%;
			}
		</style>
	</head>

	<body>
		<div id="div1">
			<ul>
				<li><img src="http://www.qdfuns.com/misc.php?mod=attach&genre=editor&aid=b4251f00ef925cba01ed49ca117e14a7" alt="" /></li>
				<li><img src="http://www.qdfuns.com/misc.php?mod=attach&genre=editor&aid=d38403825519770211acbf49459ae7d7" alt="" /></li>
				<li><img src="http://www.qdfuns.com/misc.php?mod=attach&genre=editor&aid=53c83d39c62af65db998f4945bacaec2" alt="" /></li>
				<li><img src="http://www.qdfuns.com/misc.php?mod=attach&genre=editor&aid=5509f1a642644b40c8aa98c9e2c77a83" alt="" /></li>
			</ul>
		</div>
		<script>
			var oUl = document.getElementsByTagName('ul')[0];
			var lis = oUl.getElementsByTagName('li');
			oUl.innerHTML += oUl.innerHTML;
			oUl.style.width = lis.length * lis[0].offsetWidth + 'px';
			var left = null;
			var timer = setInterval(function() {
				left -= 3;
				if(left < -oUl.offsetWidth / 2) {
					left = 0;
				}
				oUl.style.left = left + 'px'
			}, 10)
		</script>
	</body>

</html>